EBSILON®Professional Online Documentation
Used to calculate the state values for solid fuels in accordance with the cp-polynomials. The composition (elemental analysis) can be changed arbitrarily, so that pipes of the type "coal" can also be used for non-combustible substances (such as ash). The following components are possible:
Moreover, EBSILON®Professional also permits all substances available in the classic streams types (combustion ingredients and products). This portions will be calculated using the actually selected gas formulation.
Since the material values of coal not only depend on the elemental analysis, it is also possible to specify the coal type (old mode, hard coal, lignite) FCOAL and the fraction of the volatile components VOLA.
The following functions can be used:
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h = f(p, t) |
(1001) |
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t = f(p, h) |
(1003) |
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cp = f(p, h) |
(1012) |
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cp = f(p, t) |
(1017) |
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ncv |
(1021) |
net calorific value |
The net calorific value of coal can be determined from the elemental analysis only approximately. If more reliable specifications of the net calorific value are present, it is recommended to use the given value instead of the one calculated by EBSILON®Professional.
Approximately 250 different coal and biomass fuel compositions can be loaded from the default values database.
There are additional fields for the ”Coal Type”, the ”Volatiles Fractions” and for the ”Total Water Fraction” and the ”Total Ash Fraction”.
If water bound in the coal (H2OB) is present, this will be considered as a component of the coal, i.e. it is assumed that this fraction is already contained in RHOELEM. H2O on a coal stream (e.g. rain water between the coal chunks), however, will be calculated separately with the material data for H2O.
The value field ”Volatiles Fraction” is independent of the other specifications. It indicates which portion of the specified coal is volatile. This affects the thermodynamic properties of the coal (the calculation of the cp polynomials), but not the elementary combustion process. As this quantity is independent from the material composition, it is not changed if you modify the composition or switch from ”raw” to other modes.
The coal type CoalTypeEnum can be
The use of ”old mode” is compatible with previous EBSILON®Professional-releases, where the calculation of coal properties was not type-specific.
If the outlet line of a componentis a coal line, the parameter FCOAL (coal type) is always taken from the coal line when coal and oil are mixed, regardless of whether the coal line is connected to the main or secondary inlet.
The specific heat capacity cp of hard coal is according to F. Brandt, FDBR-Fachbuchreihe Band 1, 2nd edition 1991:
cp = (1. + 0.95 * VOLA) * 0.8137449 * (1.0 + 0.311 * (T/100.0) + 0.0006 * (T/100.0)2 - 0.00345 * (T/100.0)3 )
for
The specific heat capacity cp of lignite is calculated as follows:
cp = 1.577385 * ( 1.0 + 0.311 * (T/100.0) + 0.0006 * (T/100.0)2 - 0.00345 * (T/100.0)3 )
with T in °C, where the water content is determined via H2OB.
The program calculates the state variables of liquid fuels. The treatment is analogous to that of solid fuels. However, neither the coal type nor the proportion of volatile components serve as additional parameters here, but the density RHOELEM and the Z-factor ZFAC.
The possible substances and the available functions correspond to the coal substance value table.
Specific heat capacity of oil (according to F. Brandt, FDBR-Fachbuchreihe Band 1, 2nd edition 1991):
cp = ( (2.96 - 1.33 * RHO) + (0.00615 - 0.00230 * RHO) * T ) * ZFAC
RHO : density in kg/dm3 T : temperature in °C
ZFAC = 0.067 * K + 0.35
with K = TS1/3 / RHO15
TS : 50 % boiling point in K
RHO15: density at 15 °C in kg/dm3
With K = 9.7, ZFAC becomes 1.0 , e.g. with RHO15 = 8.836 kg/dm3 and TS = 543 K (EL heating oil).
The data for these oils can be loaded from the standard values: